To balance the equation a coefficient of _needs to be in front of_
KCIO4 - KCl + O2

There needs to be a 2 in front of O2.

Explanation:

That would make 4 oxygen atoms and would balance the number of atoms and mass on each side. And, in a balanced chemical equation, mass and atoms are always conserved.

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.